a clinical comparison of 2 multifocal toric xr (extended range) contact lenses

Conditions: Astigmatism

Summary: this study aims to compare the clinical performance and subjective acceptance of the comfilcon a and the omafilcon b soft contact lenses.

this will be a randomized, subject-masked, crossover, bilateral study, controlled by cross comparison. thirty subjects will use each lens type for two weeks in random sequence. follow-up visits for each lens will be performed after two weeks of wear. lenses will be worn on a daily wear basis. the final optical design of comfilcon a contact lens was optimized to improve the quality and two further studies (cv-18-10 and cv-18-11) were conducted after completion of this study to evaluate the modified optical design.

Eligibility criteria:
inclusion criteria: * subjects will only be eligible for the study if: 1. they are aged 40 - 70 years, inclusive. 2. they understand their rights as a research subject and are willing and able to sign a statement of informed consent. 3. they are willing and able to follow the protocol. 4. they have successfully completed the non-dispensing study (c16-597) as the lenses to be worn on this study (c16-599) are predetermined from their participation on study c16-597. 5. they have a contact lens spherical prescription between +10.00 to -10.00d (diopters) (inclusive). 6. they have astigmatism between of -0.75 and -5.75dc (based on the calculated ocular refraction) in each eye. 7. they have an add component to their spectacle refraction (between +0.75 and +2.50ds). 8. they can be satisfactorily fitted with the study lenses. 9. they can attain at least 0.30 logmar binocular distance high contrast visual acuity with the study lenses within the available power range. 10. they have successfully worn soft contact lenses in the last two years. 11. they are willing to comply with the wear schedule (at least five days per week and for at least six hours per day). 12. they agree not to participate in other clinical research for the duration of this study. 13. they own a wearable pair of spectacles. exclusion criteria: * subjects will not be eligible to take part in the study if: 1. they have an ocular disorder which would normally contra-indicate contact lens wear. 2. they have a systemic disorder which would normally contra-indicate contact lens wear. 3. they are using any topical medication such as eye drops or ointment. 4. they have had cataract surgery. 5. they have had corneal refractive surgery. 6. they have any corneal distortion resulting from previous hard or rigid lens wear or have keratoconus. 7. they are pregnant or breast-feeding. 8. they have any clinically meaningful slit lamp findings contraindicating contact lens wear (e.g. ≥ grade 3 finding of oedema, corneal neovascularisation, corneal staining, tarsal abnormalities, conjunctival injection, blepharitis/meibomian gland dysfunction) on the efron classification scale or any other ocular abnormality that in the opinion of the investigator would contraindicate contact lens wear. 9. they have any infectious disease (e.g. hepatitis) which would, in the opinion of the investigator, contraindicate contact lens wear or pose a risk to study personnel; or they have any immunosuppressive disease (e.g. hiv). 10. they have a history of anaphylaxis or severe allergic reaction. 11. they have taken part in any other contact lens or care solution clinical trial or research, within two weeks prior to starting this study.